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Old 24th July 2011, 02:54 AM   #11
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The lumped sum equivalent of the distributed parameter network that describes wires works perfectly for predicting cable behavior in electronic components and between them. There is no reason to doubt that the same effect created by strangely constructed wire intended to produce a given frequency filtering effect can be achieved far more predictably and cheaply through other means such as constructing an equivalent passive filter network or using an active equalizer. The advantages of the active equalizer are numerous including great flexibility, low cost, and the fact that because the filters are between buffer amplifiers their action is entirely predictable, largely independent of the source and load impedence. Wire used as a filter network has none of these advantages.

A $1 RS 3 foot interconnect carries a 7mhz NTSC detected video signal that is indistinguishable on screen from the same signal injected as RF into tuner of the best 36" analog TV set of 11 years ago. That's 350 times the bandwidth of an audio signal and of course the response is flat down to DC. This cable has no performance flaws. Its one drawback is that it generates no significant profits for anyone either.
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Old 24th July 2011, 04:15 AM   #12
mach1 is offline mach1  Australia
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Not another cable thread

Hasn't this been done to death already?
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Old 24th July 2011, 07:12 AM   #13
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Hi,

Quote:
Originally Posted by Bill poster View Post
Reading up on this and it seems there is plenty of what some of you call 'snake oil'.
Yes, there is.

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Originally Posted by Bill poster View Post
It seems low resistance is the most important criteria.
Now there is some major snake oil right here. Anyone claiming that low resistance (beyond a point, say no more than 10% of the total DCR of bass drivers voice coil and crossover choke - meaning usually anything under 0.5 Ohm) is clearly marketing snakeoil, unsupported and in reality contrary to facts.

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Good quality 2.5mm thick cable, without silver plate looks to do the job.
If that is what you believe, sure, go for it. It may be worth to compare this to the even more incredibly cheap 1mm solid core mains ring wire (parallel the bare earth conductor with black for "-", the other is "+"), just for laughs and giggles and to see if my "low resistance in speaker cables is snakeoil" quip actually has some foundation in reality.

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Originally Posted by Bill poster View Post
Wd be interested in your views and what you use in your builds whether budget or high end.
Well, in my system I use Tempflex SCSI III ribbon cable, this has 80 very thin solid core copper conductors, silverplated, with PTFE insulation. I am usually using solid silver (goldplated or enameled) for internal wiring in speakers (and all other wiring, except mains).

The Tempflex cable is not really "Audio" cable and it is not cheap (around 5 USD per foot last time I bought some).

Ciao T
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Old 24th July 2011, 07:35 AM   #14
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Hi,

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Originally Posted by nightanole View Post
Power cords- its gone through countless feet of 12-14guage solid core, butt connectors, and screw terminals, but that last 10ft from the wall makes all the difference?
Well, anyone who has passed EE101 SHOULD be able to explain why it is precisely the the last 10 Foot that make the difference and exactly what processes contribute and how we can minimise the sensitivity of equipment to these effects and how one may construct power cable so as to significantly improve the situation with "legacy" equipment not build by applying such knowledge.

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Originally Posted by nightanole View Post
Interconnects- i havent seen anything that can beat $30 canare rg59 with crimp style ends. As a bonus do you really think the pcb traces are ofc/silver shielded bla bla bla.
So you judge "beating" by looking at cables?

For fun, you can compare Canare RG-59 and a higher grade double shielded (and thus having a much lower return path impedance) RG-Series cable that has essentially identical electrical and mechanical parameters otherwise. And you can apply correctly made soldered ground connection to that crimping and use a plug that can be made to have a very low ground resistance by allowing the plug ground collet to be tightened (e.g. older WBT style).

For extra credits, using only knowledge present in EE101, please explain why the cable with the significantly lower ground impedance end to end would be perferrable in this application and what the mechanisms involved are.

Finally, in better quality gear especially since the passing of ROHS in europe the PCB traces are often goldplated (as tin/lead plating is not compliant).

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Speaker cable- I dont think its the cable itself. I think its the ends. Most of the banana ends ive seen are 3 pieces or more (read 3 physical pieces the signal has to go through) of brass that is press fit together and then gold plated. When you take them apart most of the time they are corroded black/green where the parts meet for the pure copper pieces.
A rare bit of common sense here.

I personally prefer single piece spades, copper, not Brass. These used to be available from Radioshack in the UK cheaply, when they closed all shops I bought all the available stock in London and nearby.

Spades and good quality single piece binding posts can make a very low resistance connection and if regulary checked for tightness the results are very long term reliable.

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Originally Posted by nightanole View Post
Personally for speaker wire I would go with silver plated teflon with 2 sets of twisted pair 18 gauge just for toughness/flexibility/corrosion. You can get what, 500ft for $50.
I would instead suggest that if cost is a major concern, plenum rated Cat5/5e/6 etc Network cable (the solid core version used for the main wiring) can be used (make sure the conductors are copper). It is normally 8 pcs of 24 Gauge solid copper in PE or PTFE/FEP insulation.

Many years ago I published notes on the FFRC Speaker cable on TNT-Audio. These writings and subsequent articles introducing more complex constructions by others may be a good idea to read.

Such wire is very cheap, I regularly used to blag partially used boxes from network contractors for ought... Even paying for 300m Reel will not bankrupt anyone.

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Any tips on bananas?
Yes, Eat them if you like them, but keep them away from speaker cables.

Ciao T
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Old 24th July 2011, 07:40 AM   #15
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Hi,

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Originally Posted by DBMandrake View Post
Amplifiers have a certain output impedance, in modern solid state amplifiers this is very low, typically <0.2 ohms. You can calculate it based on the quoted "damping factor". For example a damping factor of 40 rated at 8 ohms is 8/40 = 0.2 ohms. Valve amplifiers typically have a much higher output impedance of a few ohms.
All this is meaningless. Any REAL calculation of the "damping factor" must include the speakers voice coil DCR and the resistance of any inductors.

In which case we see that real damping factor quickly approach unity, as long as we take the rule "rated impedance must not be greater speakers minimum impedance plus 30%".

In other words, the whole talk about damping factor is one big red herring or bottle of snake oil.

Sure, there is a sensible limit as how much series resistance will be too much, however, given that moving ones head a few inches easily causes frequency response changes of many dB, even 1-2dB change in frequency response is in practice unlikely to be meaningful in the sense of degrading performance.

Ciao T
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Old 24th July 2011, 07:45 AM   #16
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Quote:
Originally Posted by mach1 View Post
Not another cable thread

Hasn't this been done to death already?
Yes but some things never (and I would propose can never) reach a satisfactory conclusion

Provided everyone keeps it civil it shouldn't be a problem. Those who feel it has been done to death try to look away and pretend that it's not happening again

Tony.
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Old 24th July 2011, 12:10 PM   #17
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I've also seen those green insides of corroded banana plugs-Are Neutrik connectors a much better way to go?
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Old 24th July 2011, 12:14 PM   #18
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Hi,

Quote:
Originally Posted by Bill poster View Post
I've also seen those green insides of corroded banana plugs-Are Neutrik connectors a much better way to go?
The Neutrik Speakon connector is a MASSIVELY BETTER alternative to anything in use in High End HiFi, but it has little to no compatibility with general HiFi gear.

If you do not need "normal HiFi compatibility" make a straight bee-line to Speakon and consider using them bi-wired as well...

Ciao T
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Old 24th July 2011, 12:39 PM   #19
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Dum question but why are they 3 pole?

NC-3FDL1BAG - Neutrik XLR chassis connector 3 poles - Europe Audio

DLT-123 - NEUTRIK DMX resistance terminating plugs - Europe Audio
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Old 24th July 2011, 12:42 PM   #20
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Hi,

Because they are designed for line level balanced signals, not for speaker connections.

For speaker connections the correct connector is called Speakon and Neutrik has also an alternative, much improved power connector to replace IEC, called Powercon.

I can strongly recommend both of these.

For Balanced Line connections I prefer all plastic Cliff brand XLR's.

Ciao T
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